Method and means for producing smoke and fog effects



Feb. 9, 1937. H. H. BATT METHOD AND MEANS FOR PRODUCING SMOKE AND FOG EFFECTS Filed Feb. 9, 1935 ATTORNEYS Patented Feb. 9, 1937 UNITED ST T S PATENT OFFICE.

METHOD AND MEANS FOR PRODUCING SMOKE AND FOG EFFECTS My invention relates to method and apparatus for producing smoke and fog efiects particularly adapted to the production of smoke screens and smoke and fog efiects for stage and cinema purposes.

In the production of smoke eflects, such as are commonly employed for the production of smoke screens in army and navy maneuvers, it is the common practice to eject from a suitable device a cloud of smoke consisting essentially of vaporized oil and chemicals which together will produce an opaque vapor.

The characteristic, however, of such vapor and the methods now employed to produce the same are such that the vapors when ejected from the producing device are relatively warm and for this reason rise rapidly, thus detracting from their desired eifect which is to maintain the cloud or screen close to the ground or surface over which the vapor is to lie.

When such vapors are to be employed for the production of smoke or fog efiects in stage settings'or in cinema productions, it is essential that these vapors be maintained close to the floor of the stage or set even though vapors are so disseminated that they are relatively thin and trans parent as is required for this purpose. Again the production and dissemination of heated vapors'is undesirable since these vapors, particularly when spread thinly, will rapidly rise, removing the vatity of liquid oil or chemicals the greatest possible volume of smoke orfog.

It is, therefore, anobject of this invention to provide a method for producing smoke and fog effects by vaporizing oil and chemical mixtures of the character now used for this result, and

in treating such vapors so produced to cause them to lie close to the floor of the stage or setting, or, in, the case of smoke screens, to cause them to lie close to the ground or other surface over which they may be projected.

Another object of the invention is to provide a method of producing relatively great volumes of vapor for smoke and fog effects, in which the vapors so produced will tend to remain at low levels even though thinly distributed.

Another object of the invention is to provide.

an apparatus for producing such smoke or fog eflects in which the vapor may be produced from suitable liquids injected into an air stream, heatmg the vaporous mixture to assist in the vaporization of the liquids, and then chilling said vaporous mixture to cause them to be heavier, or equal in weight, to the atmosphere into which they are projected.

Other objects and advantages will be apparent from a study of the following specification, read in connection with the accompanying drawing,

wherein Figure 1 is a perspective view of a machine for producing fog eflects, constructed in accordance with my invention; and

Figure 2 is a detail view of an atomizer and jet which may be employed in the practice of my invention.

Referring to the drawing, I have illustrated in Fig. 1 a machine for producing fog and smoke effects in accordance with my invention, the embodiment of which is that of a portable machine particularly adapted for the production of fog effects for stage and cinema settings, though it will be understood by those skilled in the art that the apparatus disclosed will be equally well adapt ed to the production of low hanging smoke screens.

Referring to the drawing, I have illustrated in Fig. 1 a base I which may be employed as the bottom of a suitable housing constructed oi end plates 2 and 3, to which may be attached side ,walls 4 (one of which is illustrated as being re- 'moved to permit access to the interior of the housing).

Mounted upon one of the side walls 4 may be a.suitable tank 5 containing a mixture of oil and chemicals commonly employed in the production of smoke screens used in aviation or used to produce smoke trailers employed by aviators in sky-writing or writing on smoke in the sky. Such materials are usually in the liquid state and may be placed in the tank 5 through a suitable filler opening 6 and pressure built up within the'tank 5 by means of a suitable pump I connected by means of a pipe 8 to the tank 5. The pressure within the tank may be indicated on a suitable gauge 9 so as to permit the operator of the machine to determine whether or not sufficient pressure has been built up within the tank.

A vaporizer Ill is illustrated as being of a conduit form of a length of relatively large pipe stituting an extension of the conduit formed by the vaporizer it and extending to the desired point on the set at which the vapor or 05 is to be projected thereon.

In nnecting the tank 5 and the vaporizer it is a pipe or nipple it which extends into and it the vaporizer E to an injector nozzle i1 located within the vaporizer m. The nozzle H is provided with the usual needle valve controlled by a valve rod is extending through the front wall 8 of the housing and having a suitable adjusting handle I It thereon. permitting ustment of the needle valve to any desired position to feed a predetermined quantity oi the oil or chemical from the tank into the vaporizer it. I prefer to provide a cutofi valve it in the nipple it, which valve may be controlled by a suitable rod 2i also extending through the front plate 3 of the housing and the t it will be materially assisted if the air from the blower i2 is heated, or if the vaporizer it is heated, and for this purpose I have provided a heating coil to surrounding the vaporizer it throughout substantially its full length so that the application of electric current to the heater coils 23 will heat the vaporizer pipe and thus assist in thevaporization of the chemical. oil or other liquid used to produce a greater quantity oi'vapor or smoke therefrom.

Whit the heat applied to the vaporizer it may be supplied thereto in any suitable manner, I prefer to employ the coils 23 as electrical heating coils connected by means of conductors a, b to a switch 2%. Current may be supplied to the switch 26 and to the motor 53 by means of a suitable conductor 25 connected to attachment plug 28 insertable in any of the well-known electrical outlet receptacles. The motor 83 may be supplied with current by means of conductors c and d in which may be interposed a rheostat the by which the motor and blower speed may be regulated.

The vapors issuing from the outer end id of the vaporizer ill will, by reason of the heating of the vaporizer it, be relatively warm and thus ii these vapors are projected directly on the stage, there will be a tendency for the vapors or fog to rapidly rise from the floor thereon which would spoil the simulation to the natural characteristics of fog. This may beovercome, however, without destroying or spoiling in any manner the vapors or efiects of the vapors by passing' the smoke or fog from the vaporizer iii through a suitablev cooling agentillustrated herein as a box or tank 27 through which the pipe 85 extends, the tank 21 being packed with ice 28 or in any other manner refrigerated so as to cool ofi the vaporous mixture of air and log to such extent that when this fog is passed from the exit end 29 of the pipe IE it will be so cooled as to be. heavier than, or equal in weight. to. the surrounding atmosphere into provided with a handle 22 thereon permitting apropos which it is projected and thus cause them to hang close to the floor of the stage or setting over which it is projected. The chilling of such fog may be to any desired temperature above that necessary to condense the vapors back into the liquid state.

It will be apparent to those skilled in the art that the exit end it of the pipe it may be carried to any desired location or locations on the set, and the vapors distributed upon the set by suitable distributing pipes connected to the exit end 29 of the pipe it.

While any suitable injector l'l may be employed, I prefer to use a small needle valve nozzle, illustrated particularly in Fig. 2, projecting into a Venturi tube 36 located within the interior of the vaporizer idea that the blast of air from the blower 82 will cause a suction at the venturi 30 to assist in rapidly disseminating the liquid from the 5 into the air stream.

If desired, the temperature of the vaporizer it may be readily and accurately .controlled by means of a pyrometer or thermocable 3! projecting into the vaporizer It and connected with a suitable dial it on the front wall s of the housing.

It will be understood by those ed in the art that the apparatus herein descri may be employed with ordinary oil and chemical tures for the production of smoke screens in aviation, and may be employed in my system for producing smoke screens for fog efiects for stage and cinema productions, in which, while the liquids so used are heated in the vaporizer it to produce the greatest quantity of smoke from a given quantity of liquid. the vapors so produced are subsequently chilled prior to their ejection into the atmosphere in which they are to be :fects ranging from a heavy, dense fog to a relatively thin fog which may be maintained by regulation of the quantity of vapor produced at any desired value. her, it will be understood by those skilled in the art that by employing the step of Hi): the vapors produced as fog or smoke screen ective, a smoke screen of great density may be provided which 11 hang close to the ground, ocean or other ace over which the vapors are projected, and which will maintain this position for a relatively great length of time, namely until the surrounding atmosphere has so diluted the vapors or temperature of the surrounding atmosphere has heated the vapors so that they tend to rise.

While I have shown anddescribed the pre-- ferred embodiment of my invention, it is to be understood that I do not wish to be limited to any of the details of construction shown herein, except as defined in too appended claims.

I claim:

1. The method of producing smoke or iog effects, which consists in injecting an opaquevapor producing liquid into an air stream. heating the air to assist the vaporization, and chill- I 2,070,035 ing said vaporous mixture so produced to cause it to be as heavy, or heavier than the atmosphere into which it is released.

fects, which consists in injecting an opaquevapor producing liquid into an air stream, heating the air to assist in vaporization of said liquid, passing said vaporous mixture so produced through a cooling medium to chill the same to cause it to be as heavy or heavier than the surrounding atmosphere, and then releasing said vaporous mixture to the atmosphere subsequent to said chilling of said vaporous mixture.

3. The method of producing smoke and fog efiects which consists in injecting an opaquevapor producing liquid into an air stream, conducting said air stream through a heating medium to assist in the vaporization of said liquid, and then conducting said air stream through a cooling medium to chill the vaporous mixture s0 produced to cause it to be as heavy, or heavier than the surrounding atmosphere prior to release of said vapors to the atmosphere.

4. Ina machine for producing smoke and fog effects. a conduit, means for blowing a stream of air through said conduit toward an exit, means for injecting an opaque-vapor producing liquid into said conduit near one end thereof, means for heating a portion of said conduit spaced from said injecting means in the direction of the flow of air through said conduit, and means for chilling a portion of said conduit spaced from said heated portion thereof in the direction of the flow of the air stream through said conduit.

5. In a machine for producing smoke and fog eflects, a conduit. means for blowing a stream of air through said conduit toward an exit, means for injecting an opaque-vapor producing liquid into said conduit near one end thereof, an electric heating element surrounding a portion of said conduit near said injecting means, "and means for chilling a portion of said conduit spaced from the heated portion thereof in the direction of the flow of the air stream through said conduit.

6. The method of producing fog or smoke effects which consists in vaporizing a liquid to produce an opaque vaporous mixture with air, heating said liquid during vaporization thereof, chilling said vaporous mixture to cause it to be as heavy or heavier than the surrounding atmosphere, and projecting said vaporous mixture intosaid atmosphere after being so chilled.

HOWARD H. BA'I'I. 

